title: Mesenchymal stem cell differentiation on electrochemically modified titanium: an optimized approach for biomedical  applications.
abstract: OBJECTIVE
  To speed up the osteointegration process, surface-treated titanium has been widely used in dental and orthopedic applications. The present work describes a new silicon-based anodic spark deposition (ASD) treatment and investigates the properties of the surfaces obtained, focusing on their capability to modulate the osteogenic differentiation potential of adult mesenchymal stem cells (MSCs).
  
  
  METHODS
  The surfaces examined were obtained from commercially pure grade 2 titanium by a single-step ASD (SUM) eventually followed by a thermal treatment in alkali solution (SUMNa), while acid-etched titanium (AE; NextMaterials s.r.l.) was selected as a control. Their morphology, elemental composition, crystallographic structure of the Ti2O layer, wettability and topography were evaluated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, thin-film X-ray diffraction, contact angle measurements and laser profilometry, respectively. MSCs' response to surface properties was assessed by examining cell morphology and viability by scanning electron microscopy and Alamar Blue assay®, while their osteogenic differentiation potential was investigated by evaluating the levels of the enzyme alkaline phosphatase (ALP) and the degree of calcium accumulation by Alizarin Red-S (AR-S) staining.
  
  
  RESULTS
  The proposed ASD treatment has allowed the obtaining of surfaces with round-shaped micrometric pores, enriched in calcium, phosphorus and silicon and significantly more wettable than controls; furthermore, the treatment has been shown to promote MSC proliferation and the degree of in vitro mineralization.
  
  
  CONCLUSIONS
  The described ASD treatment may be an effective technique to modify the surface cues of titanium implants, aiming at enhancing the conveying of osteoprogenitor cells and their functional differentiation in bone cells.
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Polytechnic of Milan, Milano - Italy. mtunesi@chem.polimi.it
authors.forename: Marta
authors.initials: M
authors.lastname: Tunesi
authors.forename: Caterina
authors.initials: C
authors.lastname: Bossio
authors.forename: Noemi
authors.initials: N
authors.lastname: Tonna
authors.forename: Cinzia
authors.initials: C
authors.lastname: Della Valle
authors.forename: Fabio
authors.initials: F
authors.lastname: Bianco
authors.forename: Roberto
authors.initials: R
authors.lastname: Chiesa
authors.forename: Carmen
authors.initials: C
authors.lastname: Giordano
mesh_terms: D000818:Animals; D035843:Biomedical Research / Q000295:instrumentation / Q000379:methods / Q000592:standards; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D055664:Electrochemical Techniques; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D046509:Tissue Culture Techniques / Q000295:instrumentation; D054457:Tissue Scaffolds / Q000737:chemistry; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D014025:Titanium